Several methods have been proposed for pattern inspection using a SEM image. For example, there is a method of designating a portion to be inspected on the SEM image using design data. There is another method of detecting a defect by comparing patterns of the design data with those on the SEM image.
However, if there is distortion in the SEM image, correspondence between the SEM image and the design data cannot be ensured even by using the above methods and thus accurate inspection cannot be performed.
For example, Japanese Laid-open Patent Publication No. 2011-169835 discloses such conventional technologies noted above.